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4 daysmodule: Make sure relocations are applied to the per-CPU sectionSebastian Andrzej Siewior
The per-CPU data section is handled differently than the other sections. The memory allocations requires a special __percpu pointer and then the section is copied into the view of each CPU. Therefore the SHF_ALLOC flag is removed to ensure move_module() skips it. Later, relocations are applied and apply_relocations() skips sections without SHF_ALLOC because they have not been copied. This also skips the per-CPU data section. The missing relocations result in a NULL pointer on x86-64 and very small values on x86-32. This results in a crash because it is not skipped like NULL pointer would and can't be dereferenced. Such an assignment happens during static per-CPU lock initialisation with lockdep enabled. Allow relocation processing for the per-CPU section even if SHF_ALLOC is missing. Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202506041623.e45e4f7d-lkp@intel.com Fixes: 1a6100caae425 ("Don't relocate non-allocated regions in modules.") #v2.6.1-rc3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Link: https://lore.kernel.org/r/20250610163328.URcsSUC1@linutronix.de Signed-off-by: Daniel Gomez <da.gomez@samsung.com> Message-ID: <20250610163328.URcsSUC1@linutronix.de>
4 daysmodule: Avoid unnecessary return value initialization in move_module()Petr Pavlu
All error conditions in move_module() set the return value by updating the ret variable. Therefore, it is not necessary to the initialize the variable when declaring it. Remove the unnecessary initialization. Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Daniel Gomez <da.gomez@samsung.com> Link: https://lore.kernel.org/r/20250618122730.51324-3-petr.pavlu@suse.com Signed-off-by: Daniel Gomez <da.gomez@samsung.com> Message-ID: <20250618122730.51324-3-petr.pavlu@suse.com>
4 daysmodule: Fix memory deallocation on error path in move_module()Petr Pavlu
The function move_module() uses the variable t to track how many memory types it has allocated and consequently how many should be freed if an error occurs. The variable is initially set to 0 and is updated when a call to module_memory_alloc() fails. However, move_module() can fail for other reasons as well, in which case t remains set to 0 and no memory is freed. Fix the problem by initializing t to MOD_MEM_NUM_TYPES. Additionally, make the deallocation loop more robust by not relying on the mod_mem_type_t enum having a signed integer as its underlying type. Fixes: c7ee8aebf6c0 ("module: add stop-grap sanity check on module memcpy()") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Daniel Gomez <da.gomez@samsung.com> Link: https://lore.kernel.org/r/20250618122730.51324-2-petr.pavlu@suse.com Signed-off-by: Daniel Gomez <da.gomez@samsung.com> Message-ID: <20250618122730.51324-2-petr.pavlu@suse.com>
2025-06-07Merge tag 'kbuild-v6.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which exports a symbol only to specified modules - Improve ABI handling in gendwarfksyms - Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n - Add checkers for redundant or missing <linux/export.h> inclusion - Deprecate the extra-y syntax - Fix a genksyms bug when including enum constants from *.symref files * tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits) genksyms: Fix enum consts from a reference affecting new values arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES} efi/libstub: use 'targets' instead of extra-y in Makefile module: make __mod_device_table__* symbols static scripts/misc-check: check unnecessary #include <linux/export.h> when W=1 scripts/misc-check: check missing #include <linux/export.h> when W=1 scripts/misc-check: add double-quotes to satisfy shellcheck kbuild: move W=1 check for scripts/misc-check to top-level Makefile scripts/tags.sh: allow to use alternative ctags implementation kconfig: introduce menu type enum docs: symbol-namespaces: fix reST warning with literal block kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION docs/core-api/symbol-namespaces: drop table of contents and section numbering modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time kbuild: move kbuild syntax processing to scripts/Makefile.build Makefile: remove dependency on archscripts for header installation Documentation/kbuild: Add new gendwarfksyms kABI rules Documentation/kbuild: Drop section numbers ...
2025-06-05alloc_tag: handle module codetag load errors as module load failuresSuren Baghdasaryan
Failures inside codetag_load_module() are currently ignored. As a result an error there would not cause a module load failure and freeing of the associated resources. Correct this behavior by propagating the error code to the caller and handling possible errors. With this change, error to allocate percpu counters, which happens at this stage, will not be ignored and will cause a module load failure and freeing of resources. With this change we also do not need to disable memory allocation profiling when this error happens, instead we fail to load the module. Link: https://lkml.kernel.org/r/20250521160602.1940771-1-surenb@google.com Fixes: 10075262888b ("alloc_tag: allocate percpu counters for module tags dynamically") Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reported-by: Casey Chen <cachen@purestorage.com> Closes: https://lore.kernel.org/all/20250520231620.15259-1-cachen@purestorage.com/ Cc: Daniel Gomez <da.gomez@samsung.com> Cc: David Wang <00107082@163.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-06-02Merge tag 'modules-6.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux Pull module updates from Petr Pavlu: - Make .static_call_sites in modules read-only after init The .static_call_sites sections in modules have been made read-only after init to avoid any (non-)accidental modifications, similarly to how they are read-only after init in vmlinux - The rest are minor cleanups * tag 'modules-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: module: Remove outdated comment about text_size module: Make .static_call_sites read-only after init module: Add a separate function to mark sections as read-only after init module: Constify parameters of module_enforce_rwx_sections()
2025-05-25Merge tag 'mm-hotfixes-stable-2025-05-25-00-58' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "22 hotfixes. 13 are cc:stable and the remainder address post-6.14 issues or aren't considered necessary for -stable kernels. 19 are for MM" * tag 'mm-hotfixes-stable-2025-05-25-00-58' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits) mailmap: add Jarkko's employer email address mm: fix copy_vma() error handling for hugetlb mappings memcg: always call cond_resched() after fn() mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios mm: vmalloc: only zero-init on vrealloc shrink mm: vmalloc: actually use the in-place vrealloc region alloc_tag: allocate percpu counters for module tags dynamically module: release codetag section when module load fails mm/cma: make detection of highmem_start more robust MAINTAINERS: add mm memory policy section MAINTAINERS: add mm ksm section kasan: avoid sleepable page allocation from atomic context highmem: add folio_test_partial_kmap() MAINTAINERS: add hung-task detector section taskstats: fix struct taskstats breaks backward compatibility since version 15 mm/truncate: fix out-of-bounds when doing a right-aligned split MAINTAINERS: add mm reclaim section MAINTAINERS: update page allocator section mm: fix VM_UFFD_MINOR == VM_SHADOW_STACK on USERFAULTFD=y && ARM64_GCS=y mm: mmap: map MAP_STACK to VM_NOHUGEPAGE only if THP is enabled ...
2025-05-25module: Account for the build time module name manglingPeter Zijlstra
Sean noted that scripts/Makefile.lib:name-fix-token rule will mangle the module name with s/-/_/g. Since this happens late in the build, only the kernel needs to bother with this, the modpost tool still sees the original name. Reported-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-05-25module: Extend the module namespace parsingPeter Zijlstra
Instead of only accepting "module:${name}", extend it with a comma separated list of module names and add tail glob support. That is, something like: "module:foo-*,bar" is now possible. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-05-25module: Add module specific symbol namespace supportPeter Zijlstra
Designate the "module:${modname}" symbol namespace to mean: 'only export to the named module'. Notably, explicit imports of anything in the "module:" space is forbidden. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-05-25module: release codetag section when module load failsDavid Wang
When module load fails after memory for codetag section is ready, codetag section memory will not be properly released. This causes memory leak, and if next module load happens to get the same module address, codetag may pick the uninitialized section when manipulating tags during module unload, and leads to "unable to handle page fault" BUG. Link: https://lkml.kernel.org/r/20250519163823.7540-1-00107082@163.com Fixes: 0db6f8d7820a ("alloc_tag: load module tags into separate contiguous memory") Closes: https://lore.kernel.org/all/20250516131246.6244-1-00107082@163.com/ Signed-off-by: David Wang <00107082@163.com> Acked-by: Suren Baghdasaryan <surenb@google.com> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-18module: Remove outdated comment about text_sizeValentin Schneider
The text_size bit referred to by the comment has been removed as of commit ac3b43283923 ("module: replace module_layout with module_memory") and is thus no longer relevant. Remove it and comment about the contents of the masks array instead. Signed-off-by: Valentin Schneider <vschneid@redhat.com> Link: https://lore.kernel.org/r/20250429113242.998312-23-vschneid@redhat.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-05-18module: Make .static_call_sites read-only after initPetr Pavlu
Section .static_call_sites holds data structures that need to be sorted and processed only at module load time. This initial processing happens in static_call_add_module(), which is invoked as a callback to the MODULE_STATE_COMING notification from prepare_coming_module(). The section is never modified afterwards. Make it therefore read-only after module initialization to avoid any (non-)accidental modifications. Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20250306131430.7016-4-petr.pavlu@suse.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-05-18module: Add a separate function to mark sections as read-only after initPetr Pavlu
Move the logic to mark special sections as read-only after module initialization into a separate function, along other related code in strict_rwx.c. Use a table with names of such sections to make it easier to add more. Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20250306131430.7016-3-petr.pavlu@suse.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-05-18module: Constify parameters of module_enforce_rwx_sections()Petr Pavlu
Minor cleanup, this is a non-functional change. Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20250306131430.7016-2-petr.pavlu@suse.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-05-12kbuild: Require pahole <v1.28 or >v1.29 with GENDWARFKSYMS on X86Sami Tolvanen
With CONFIG_GENDWARFKSYMS, __gendwarfksyms_ptr variables are added to the kernel in EXPORT_SYMBOL() to ensure DWARF type information is available for exported symbols in the TUs where they're actually exported. These symbols are dropped when linking vmlinux, but dangling references to them remain in DWARF. With CONFIG_DEBUG_INFO_BTF enabled on X86, pahole versions after commit 47dcb534e253 ("btf_encoder: Stop indexing symbols for VARs") and before commit 9810758003ce ("btf_encoder: Verify 0 address DWARF variables are in ELF section") place these symbols in the .data..percpu section, which results in an "Invalid offset" error in btf_datasec_check_meta() during boot, as all the variables are at zero offset and have non-zero size. If CONFIG_DEBUG_INFO_BTF_MODULES is enabled, this also results in a failure to load modules with: failed to validate module [$module] BTF: -22 As the issue occurs in pahole v1.28 and the fix was merged after v1.29 was released, require pahole <v1.28 or >v1.29 when GENDWARFKSYMS is enabled with DEBUG_INFO_BTF on X86. Reported-by: Paolo Pisati <paolo.pisati@canonical.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-03-31Merge tag 'trace-ringbuffer-v6.15-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull ring-buffer updates from Steven Rostedt: - Restructure the persistent memory to have a "scratch" area Instead of hard coding the KASLR offset in the persistent memory by the ring buffer, push that work up to the callers of the persistent memory as they are the ones that need this information. The offsets and such is not important to the ring buffer logic and it should not be part of that. A scratch pad is now created when the caller allocates a ring buffer from persistent memory by stating how much memory it needs to save. - Allow where modules are loaded to be saved in the new scratch pad Save the addresses of modules when they are loaded into the persistent memory scratch pad. - A new module_for_each_mod() helper function was created With the acknowledgement of the module maintainers a new module helper function was created to iterate over all the currently loaded modules. This has a callback to be called for each module. This is needed for when tracing is started in the persistent buffer and the currently loaded modules need to be saved in the scratch area. - Expose the last boot information where the kernel and modules were loaded The last_boot_info file is updated to print out the addresses of where the kernel "_text" location was loaded from a previous boot, as well as where the modules are loaded. If the buffer is recording the current boot, it only prints "# Current" so that it does not expose the KASLR offset of the currently running kernel. - Allow the persistent ring buffer to be released (freed) To have this in production environments, where the kernel command line can not be changed easily, the ring buffer needs to be freed when it is not going to be used. The memory for the buffer will always be allocated at boot up, but if the system isn't going to enable tracing, the memory needs to be freed. Allow it to be freed and added back to the kernel memory pool. - Allow stack traces to print the function names in the persistent buffer Now that the modules are saved in the persistent ring buffer, if the same modules are loaded, the printing of the function names will examine the saved modules. If the module is found in the scratch area and is also loaded, then it will do the offset shift and use kallsyms to display the function name. If the address is not found, it simply displays the address from the previous boot in hex. * tag 'trace-ringbuffer-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Use _text and the kernel offset in last_boot_info tracing: Show last module text symbols in the stacktrace ring-buffer: Remove the unused variable bmeta tracing: Skip update_last_data() if cleared and remove active check for save_mod() tracing: Initialize scratch_size to zero to prevent UB tracing: Fix a compilation error without CONFIG_MODULES tracing: Freeable reserved ring buffer mm/memblock: Add reserved memory release function tracing: Update modules to persistent instances when loaded tracing: Show module names and addresses of last boot tracing: Have persistent trace instances save module addresses module: Add module_for_each_mod() function tracing: Have persistent trace instances save KASLR offset ring-buffer: Add ring_buffer_meta_scratch() ring-buffer: Add buffer meta data for persistent ring buffer ring-buffer: Use kaslr address instead of text delta ring-buffer: Fix bytes_dropped calculation issue
2025-03-30Merge tag 'modules-6.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux Pull modules updates from Petr Pavlu: - Use RCU instead of RCU-sched The mix of rcu_read_lock(), rcu_read_lock_sched() and preempt_disable() in the module code and its users has been replaced with just rcu_read_lock() - The rest of changes are smaller fixes and updates * tag 'modules-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (32 commits) MAINTAINERS: Update the MODULE SUPPORT section module: Remove unnecessary size argument when calling strscpy() module: Replace deprecated strncpy() with strscpy() params: Annotate struct module_param_attrs with __counted_by() bug: Use RCU instead RCU-sched to protect module_bug_list. static_call: Use RCU in all users of __module_text_address(). kprobes: Use RCU in all users of __module_text_address(). bpf: Use RCU in all users of __module_text_address(). jump_label: Use RCU in all users of __module_text_address(). jump_label: Use RCU in all users of __module_address(). x86: Use RCU in all users of __module_address(). cfi: Use RCU while invoking __module_address(). powerpc/ftrace: Use RCU in all users of __module_text_address(). LoongArch: ftrace: Use RCU in all users of __module_text_address(). LoongArch/orc: Use RCU in all users of __module_address(). arm64: module: Use RCU in all users of __module_text_address(). ARM: module: Use RCU in all users of __module_text_address(). module: Use RCU in all users of __module_text_address(). module: Use RCU in all users of __module_address(). module: Use RCU in search_module_extables(). ...
2025-03-28module: Add module_for_each_mod() functionSteven Rostedt
The tracing system needs a way to save all the currently loaded modules and their addresses into persistent memory so that it can evaluate the addresses on a reboot from a crash. When the persistent memory trace starts, it will load the module addresses and names into the persistent memory. To do so, it will call the module_for_each_mod() function and pass it a function and data structure to get called on each loaded module. Then it can record the memory. This only implements that function. Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: linux-modules@vger.kernel.org Link: https://lore.kernel.org/20250305164608.962615966@goodmis.org Acked-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-03-10module: Remove unnecessary size argument when calling strscpy()Thorsten Blum
The size parameter is optional and strscpy() automatically determines the length of the destination buffer using sizeof() if the argument is omitted. This makes the explicit sizeof() unnecessary. Remove it to shorten and simplify the code. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Link: https://lore.kernel.org/r/20250308194631.191670-2-thorsten.blum@linux.dev Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Replace deprecated strncpy() with strscpy()Thorsten Blum
strncpy() is deprecated for NUL-terminated destination buffers; use strscpy() instead. The destination buffer ownername is only used with "%s" format strings and must therefore be NUL-terminated, but not NUL- padded. No functional changes intended. Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Link: https://lore.kernel.org/r/20250307113546.112237-2-thorsten.blum@linux.dev Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in all users of __module_text_address().Sebastian Andrzej Siewior
__module_text_address() can be invoked within a RCU section, there is no requirement to have preemption disabled. Replace the preempt_disable() section around __module_text_address() with RCU. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-16-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in all users of __module_address().Sebastian Andrzej Siewior
__module_address() can be invoked within a RCU section, there is no requirement to have preemption disabled. Replace the preempt_disable() section around __module_address() with RCU. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-15-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in search_module_extables().Sebastian Andrzej Siewior
search_module_extables() returns an exception_table_entry belonging to a module. The lookup via __module_address() can be performed with RCU protection. The returned exception_table_entry remains valid because the passed address usually belongs to a module that is currently executed. So the module can not be removed because "something else" holds a reference to it, ensuring that it can not be removed. Exceptions here are: - kprobe, acquires a reference on the module beforehand - MCE, invokes the function from within a timer and the RCU lifetime guarantees (of the timer) are sufficient. Therefore it is safe to return the exception_table_entry outside the RCU section which provided the module. Use RCU for the lookup in search_module_extables() and update the comment. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-14-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Allow __module_address() to be called from RCU section.Sebastian Andrzej Siewior
mod_find() uses either the modules list to find a module or a tree lookup (CONFIG_MODULES_TREE_LOOKUP). The list and the tree can both be iterated under RCU assumption (as well as RCU-sched). Remove module_assert_mutex_or_preempt() from __module_address() and entirely since __module_address() is the last user. Update comments. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-13-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in __is_module_percpu_address().Sebastian Andrzej Siewior
The modules list can be accessed under RCU assumption. Use RCU protection instead preempt_disable(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-12-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in find_symbol().Sebastian Andrzej Siewior
module_assert_mutex_or_preempt() is not needed in find_symbol(). The function checks for RCU-sched or the module_mutex to be acquired. The list_for_each_entry_rcu() below does the same check. Remove module_assert_mutex_or_preempt() from try_add_tainted_module(). Use RCU protection to invoke find_symbol() and update callers. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-11-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Remove module_assert_mutex_or_preempt() from try_add_tainted_module().Sebastian Andrzej Siewior
module_assert_mutex_or_preempt() is not needed in try_add_tainted_module(). The function checks for RCU-sched or the module_mutex to be acquired. The list_for_each_entry_rcu() below does the same check. Remove module_assert_mutex_or_preempt() from try_add_tainted_module(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-10-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in module_kallsyms_on_each_symbol().Sebastian Andrzej Siewior
module::kallsyms can be accessed under RCU assumption. Use rcu_dereference() to access module::kallsyms. Update callers. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-9-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in __find_kallsyms_symbol_value().Sebastian Andrzej Siewior
module::kallsyms can be accessed under RCU assumption. Use rcu_dereference() to access module::kallsyms. Update callers. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-8-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in find_module_all().Sebastian Andrzej Siewior
The modules list and module::kallsyms can be accessed under RCU assumption. Remove module_assert_mutex_or_preempt() from find_module_all() so it can be used under RCU protection without warnings. Update its callers to use RCU protection instead of preempt_disable(). Cc: Jiri Kosina <jikos@kernel.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-trace-kernel@vger.kernel.org Cc: live-patching@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250108090457.512198-7-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in module_get_kallsym().Sebastian Andrzej Siewior
The modules list and module::kallsyms can be accessed under RCU assumption. Iterate the modules with RCU protection, use rcu_dereference() to access the kallsyms pointer. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-6-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use RCU in find_kallsyms_symbol().Sebastian Andrzej Siewior
The modules list and module::kallsyms can be accessed under RCU assumption. Use rcu_dereference() to reference the kallsyms pointer in find_kallsyms_symbol(). Use a RCU section instead of preempt_disable in callers of find_kallsyms_symbol(). Keep the preempt-disable in module_address_lookup() due to __module_address(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-5-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Use proper RCU assignment in add_kallsyms().Sebastian Andrzej Siewior
add_kallsyms() assigns the RCU pointer module::kallsyms and setups the structures behind it which point to init-data. The module was not published yet, nothing can see the kallsyms pointer and the data behind it. Also module's init function was not yet invoked. There is no need to use rcu_dereference() here, it is just to keep checkers quiet. The whole RCU read section is also not needed. Use a local kallsyms pointer and setup the data structures. Assign that pointer to the data structure at the end via rcu_assign_pointer(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-4-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-03-10module: Begin to move from RCU-sched to RCU.Sebastian Andrzej Siewior
The RCU usage in module was introduced in commit d72b37513cdfb ("Remove stop_machine during module load v2") and it claimed not to be RCU but similar. Then there was another improvement in commit e91defa26c527 ("module: don't use stop_machine on module load"). It become a mix of RCU and RCU-sched and was eventually fixed 0be964be0d450 ("module: Sanitize RCU usage and locking"). Later RCU & RCU-sched was merged in commit cb2f55369d3a9 ("modules: Replace synchronize_sched() and call_rcu_sched()") so that was aligned. Looking at it today, there is still leftovers. The preempt_disable() was used instead rcu_read_lock_sched(). The RCU & RCU-sched merge was not complete as there is still rcu_dereference_sched() for module::kallsyms. The RCU-list modules and unloaded_tainted_modules are always accessed under RCU protection or the module_mutex. The modules list iteration can always happen safely because the module will not disappear. Once the module is removed (free_module()) then after removing the module from the list, there is a synchronize_rcu() which waits until every RCU reader left the section. That means iterating over the list within a RCU-read section is enough, there is no need to disable preemption. module::kallsyms is first assigned in add_kallsyms() before the module is added to the list. At this point, it points to init data. This pointer is later updated and before the init code is removed there is also synchronize_rcu() in do_free_init(). That means A RCU read lock is enough for protection and rcu_dereference() can be safely used. Convert module code and its users step by step. Update comments and convert print_modules() to use RCU. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250108090457.512198-3-bigeasy@linutronix.de Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-02-14module: don't annotate ROX memory as kmemleak_not_leak()Mike Rapoport (Microsoft)
The ROX memory allocations are part of a larger vmalloc allocation and annotating them with kmemleak_not_leak() confuses kmemleak. Skip kmemleak_not_leak() annotations for the ROX areas. Fixes: c287c0723329 ("module: switch to execmem API for remapping as RW and restoring ROX") Fixes: 64f6a4e10c05 ("x86: re-enable EXECMEM_ROX support") Reported-by: "Borah, Chaitanya Kumar" <chaitanya.kumar.borah@intel.com> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20250214084531.3299390-1-rppt@kernel.org
2025-02-03module: switch to execmem API for remapping as RW and restoring ROXMike Rapoport (Microsoft)
Instead of using writable copy for module text sections, temporarily remap the memory allocated from execmem's ROX cache as writable and restore its ROX permissions after the module is formed. This will allow removing nasty games with writable copy in alternatives patching on x86. Signed-off-by: "Mike Rapoport (Microsoft)" <rppt@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250126074733.1384926-7-rppt@kernel.org
2025-01-31Merge tag 'kbuild-v6.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Support multiple hook locations for maint scripts of Debian package - Remove 'cpio' from the build tool requirement - Introduce gendwarfksyms tool, which computes CRCs for export symbols based on the DWARF information - Support CONFIG_MODVERSIONS for Rust - Resolve all conflicts in the genksyms parser - Fix several syntax errors in genksyms * tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (64 commits) kbuild: fix Clang LTO with CONFIG_OBJTOOL=n kbuild: Strip runtime const RELA sections correctly kconfig: fix memory leak in sym_warn_unmet_dep() kconfig: fix file name in warnings when loading KCONFIG_DEFCONFIG_LIST genksyms: fix syntax error for attribute before init-declarator genksyms: fix syntax error for builtin (u)int*x*_t types genksyms: fix syntax error for attribute after 'union' genksyms: fix syntax error for attribute after 'struct' genksyms: fix syntax error for attribute after abstact_declarator genksyms: fix syntax error for attribute before nested_declarator genksyms: fix syntax error for attribute before abstract_declarator genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier genksyms: record attributes consistently for init-declarator genksyms: restrict direct-declarator to take one parameter-type-list genksyms: restrict direct-abstract-declarator to take one parameter-type-list genksyms: remove Makefile hack genksyms: fix last 3 shift/reduce conflicts genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts genksyms: reduce type_qualifier directly to decl_specifier genksyms: rename cvar_qualifier to type_qualifier ...
2025-01-28Merge tag 'driver-core-6.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and debugfs updates from Greg KH: "Here is the big set of driver core and debugfs updates for 6.14-rc1. Included in here is a bunch of driver core, PCI, OF, and platform rust bindings (all acked by the different subsystem maintainers), hence the merge conflict with the rust tree, and some driver core api updates to mark things as const, which will also require some fixups due to new stuff coming in through other trees in this merge window. There are also a bunch of debugfs updates from Al, and there is at least one user that does have a regression with these, but Al is working on tracking down the fix for it. In my use (and everyone else's linux-next use), it does not seem like a big issue at the moment. Here's a short list of the things in here: - driver core rust bindings for PCI, platform, OF, and some i/o functions. We are almost at the "write a real driver in rust" stage now, depending on what you want to do. - misc device rust bindings and a sample driver to show how to use them - debugfs cleanups in the fs as well as the users of the fs api for places where drivers got it wrong or were unnecessarily doing things in complex ways. - driver core const work, making more of the api take const * for different parameters to make the rust bindings easier overall. - other small fixes and updates All of these have been in linux-next with all of the aforementioned merge conflicts, and the one debugfs issue, which looks to be resolved "soon"" * tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits) rust: device: Use as_char_ptr() to avoid explicit cast rust: device: Replace CString with CStr in property_present() devcoredump: Constify 'struct bin_attribute' devcoredump: Define 'struct bin_attribute' through macro rust: device: Add property_present() saner replacement for debugfs_rename() orangefs-debugfs: don't mess with ->d_name octeontx2: don't mess with ->d_parent or ->d_parent->d_name arm_scmi: don't mess with ->d_parent->d_name slub: don't mess with ->d_name sof-client-ipc-flood-test: don't mess with ->d_name qat: don't mess with ->d_name xhci: don't mess with ->d_iname mtu3: don't mess wiht ->d_iname greybus/camera - stop messing with ->d_iname mediatek: stop messing with ->d_iname netdevsim: don't embed file_operations into your structs b43legacy: make use of debugfs_get_aux() b43: stop embedding struct file_operations into their objects carl9170: stop embedding file_operations into their objects ...
2025-01-26module: sign with sha512 instead of sha1 by defaultThorsten Leemhuis
Switch away from using sha1 for module signing by default and use the more modern sha512 instead, which is what among others Arch, Fedora, RHEL, and Ubuntu are currently using for their kernels. Sha1 has not been considered secure against well-funded opponents since 2005[1]; since 2011 the NIST and other organizations furthermore recommended its replacement[2]. This is why OpenSSL on RHEL9, Fedora Linux 41+[3], and likely some other current and future distributions reject the creation of sha1 signatures, which leads to a build error of allmodconfig configurations: 80A20474797F0000:error:03000098:digital envelope routines:do_sigver_init:invalid digest:crypto/evp/m_sigver.c:342: make[4]: *** [.../certs/Makefile:53: certs/signing_key.pem] Error 1 make[4]: *** Deleting file 'certs/signing_key.pem' make[4]: *** Waiting for unfinished jobs.... make[3]: *** [.../scripts/Makefile.build:478: certs] Error 2 make[2]: *** [.../Makefile:1936: .] Error 2 make[1]: *** [.../Makefile:224: __sub-make] Error 2 make[1]: Leaving directory '...' make: *** [Makefile:224: __sub-make] Error 2 This change makes allmodconfig work again and sets a default that is more appropriate for current and future users, too. Link: https://www.schneier.com/blog/archives/2005/02/cryptanalysis_o.html [1] Link: https://csrc.nist.gov/projects/hash-functions [2] Link: https://fedoraproject.org/wiki/Changes/OpenSSLDistrustsha1SigVer [3] Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: kdevops <kdevops@lists.linux.dev> [0] Link: https://github.com/linux-kdevops/linux-modules-kpd/actions/runs/11420092929/job/31775404330 [0] Link: https://lore.kernel.org/r/52ee32c0c92afc4d3263cea1f8a1cdc809728aff.1729088288.git.linux@leemhuis.info Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: Don't fail module loading when setting ro_after_init section RO failedChristophe Leroy
Once module init has succeded it is too late to cancel loading. If setting ro_after_init data section to read-only fails, all we can do is to inform the user through a warning. Reported-by: Thomas Gleixner <tglx@linutronix.de> Closes: https://lore.kernel.org/all/20230915082126.4187913-1-ruanjinjie@huawei.com/ Fixes: d1909c022173 ("module: Don't ignore errors from set_memory_XX()") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/d6c81f38da76092de8aacc8c93c4c65cb0fe48b8.1733427536.git.christophe.leroy@csgroup.eu Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: Split module_enable_rodata_ro()Christophe Leroy
module_enable_rodata_ro() is called twice, once before module init to set rodata sections readonly and once after module init to set rodata_after_init section readonly. The second time, only the rodata_after_init section needs to be set to read-only, no need to re-apply it to already set rodata. Split module_enable_rodata_ro() in two. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Daniel Gomez <da.gomez@samsung.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/e3b6ff0df7eac281c58bb02cecaeb377215daff3.1733427536.git.christophe.leroy@csgroup.eu Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: sysfs: Use const 'struct bin_attribute'Thomas Weißschuh
The sysfs core is switching to 'const struct bin_attribute's. Prepare for that. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-6-e267275f0f37@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: sysfs: Add notes attributes through attribute_groupThomas Weißschuh
A kobject is meant to manage the lifecycle of some resource. However the module sysfs code only creates a kobject to get a "notes" subdirectory in sysfs. This can be achieved easier and cheaper by using a sysfs group. Switch the notes attribute code to such a group, similar to how the section allocation in the same file already works. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-5-e267275f0f37@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: sysfs: Simplify section attribute allocationThomas Weißschuh
The existing allocation logic manually stuffs two allocations into one. This is hard to understand and of limited value, given that all the section names are allocated on their own anyways. Une one allocation per datastructure. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-4-e267275f0f37@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: sysfs: Drop 'struct module_sect_attr'Thomas Weißschuh
This is now an otherwise empty wrapper around a 'struct bin_attribute', not providing any functionality. Remove it. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-3-e267275f0f37@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: sysfs: Drop member 'module_sect_attr::address'Thomas Weißschuh
'struct bin_attribute' already contains the member 'private' to pass custom data to the attribute handlers. Use that instead of the custom 'address' member. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-2-e267275f0f37@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: sysfs: Drop member 'module_sect_attrs::nsections'Thomas Weißschuh
The member is only used to iterate over all attributes in free_sect_attrs(). However the attribute group can already be used for that. Use the group and drop 'nsections'. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-1-e267275f0f37@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: Constify 'struct module_attribute'Thomas Weißschuh
These structs are never modified, move them to read-only memory. This makes the API clearer and also prepares for the constification of 'struct attribute' itself. While at it, also constify 'modinfo_attrs_count'. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Petr Pavlu <petr.pavlu@suse.com> Link: https://lore.kernel.org/r/20241216-sysfs-const-attr-module-v1-3-3790b53e0abf@weissschuh.net Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
2025-01-26module: Put known GPL offenders in an arrayUwe Kleine-König
Instead of repeating the add_taint_module() call for each offender, create an array and loop over that one. This simplifies adding new entries considerably. Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Werner Sembach <wse@tuxedocomputers.com> Link: https://lore.kernel.org/r/20241115185253.1299264-2-wse@tuxedocomputers.com [ppavlu: make the array const] Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>